Rotating night shifts potentially harmful to health and longevity

The study states that it is not just about ‘quality’ sleep that these workers are unable to get. It has to do with the risk to their health. It found that among the women workforce who have been working the night shift for more than 5 years, not only are they experiencing short lifespan, but the risk of dying from cardiovascular diseases have also increased. Death by lung cancer is a likely scenario for those women who have been working rotating shifts for more than 15 years.

The study was conducted over 22 years by a team of international researchers who monitored 75,000 female registered nurses in the US through Nurses’ Health Study data. Rotating shift work was defined as working a minimum of 3 nights per month with additional days or evenings in that same month.

Each nurse was interviewed every other year and they were asked for how many years they worked the ‘rotating’ shift (as defined above). 11% of the women who worked the rotating shift for more than 6 years experienced a shorter lifespan. Risk of death from cardiovascular diseases came up to 19% when the 6 years were extended to 14 years and jumped to 23% for those who worked the rotating shift for more than 15 years. For the nurses who worked the rotating night shifts for more than 15 years, the risk of death from lung cancer was about 25%.

Previous studies have acknowledged that shift work has linkages to poor health experienced by the workers. In 2007, World Health Organization considered it carcinogenic because it interfered with the body’s circadian rhythm, which is also associated with increased risks of heart and brain problems. The new study thus further highlights the importance of a healthy circadian rhythm and its role in tumour prevention.

Eva S. Schernhammer, MD, DrPH, an associate professor of medicine at Harvard Medical School and associate epidemiologist at Brigham and Women’s Hospital said in a statement that rotating night shifts definitely showed a pattern and linkages that hampered longevity and health of the workers working these shifts. She said that these linkages warranted further exploration for better understanding of impacts to hasten solutions.